Tankless coil water heater



J. LAYTON TANKLESS COIL WA ER HEATER June 25, 1957 2 Sheets-Sheet l Filed Sept. 27. 1954 I 4 RNVENTOR AZ E 'ZZ ATTORNEY June 25, 1957 LAYTQN 2,797,069

TANKLESS con. WATER HEATER Filed Sept. 27 1954 2 Shee'ts-Sheet 2 WA TEK WA TE R ,qo-r WATER OUT INVENTOR Jae/i 16/! 2:11

ATTORNEY United States Patent TANKLESS COIL WATER HEATER Jack Layton, Cedarhurst, N. Y. Application September 27, 1954, Serial No. 458,644 6 Claims. 01. 257-243 The invention here disclosed is for a flexible, tankless water heater helical coil device suited for and easily installed into compact or intricate passages within the dome section of standard boiler burner units to provide for an instantaneous, maximum capacity and highly efficient, yet inexpensive, hot water supply.

Domestic hot water usually has been supplied by means of direct, indirect or tankless heaters. Most boiler burner units have a generator cooperating with a hot water storage tank. Others have dome sections into which conventional tankless units may be installed at the option of the user. Serious disadvantages presented themselves, however, to the installation of such tankless units therein, some of which were low capacity and impaired efficiency of the hot water supply brought about by the cramped space of the dome section, the inflexibility of the unit and the resultant reduced area of heating surface of the tankless unit. Additionally, many standard boiler burner units have dome sections which are comparatively small and contain intricate and complex passages which prohibit the installation or use of conventional or ordinary tankless units therein. In these cases the user is relegated to the use of a generator unit cooperating with a Water storage tank, which in many cases may be wholly unsuited to the users needs.

Hence, there is a need for an efficient high capacity tankless heater of low cost, which is capable of quick and easy installation within dome sections of standard boiler burner units, and having sufiicient flexibility 50 as to permit of fitting the same within intricate or cramped passages of such dome sections.

According to the present invention there is provided a compact flexible tankless water heater consisting of twin helical coils, a cover plate, gaskets and lock nuts for such installation within dome sections of standard boiler burner units, which coils are capable of being bent to facilitate fitting therewithin.

Accordingly, there is provided an easily installed device which is simple, inexpensive and compact in construction and which is designed to provide a highly eflicient, constant and abundant supply of clean, hot water at the lowest possible cost.

Other objects and details of the invention will be apparent from thefollowing description when read in connection with the accompanying drawings, wherein Fig. 1 is a top view of the device of the invention in the preferred form;

Fig. 2 is an end view of the device showing the cover plate and cross-over connections;

Fig. 3 is an endview of the coils on line 3-3 of Fig.1;

Fig. 4 is an end- View of the helix and inlet tube'on line 4-4 of Fig. l;

Fig. 5 is a top view of an alternative embodiment of the deviceof the invention; and

Fig. 6 is a top view of a boiler dome section with the tankless heater in place.

Referring to the figures, the coils 1 are fashioned of seamless drawn finned copper tubing of suitable diameter and of suflicient thickness to withstand a maximum of working pressure per square inch. The tubing may also be made of any other convenient metal possessing similar properties, but copper is preferable and admirably suited for the purpose. The finned construction of the copper tubing is desirable because its heat exchange capacity is high due to the fact that the metal in the structure thus formed has greater thermal conductivity than in a cast construction. Each of the coils is formed as follows: A tube 2 of finned copper tubing to be connected at an inlet end 3 by suitable fitting 4 to water pipes 5 has an inlet horizontal length 6 which is turned into a loop or bend 7 at its far end and the tube beyond the loop bend is fashioned into a helical coil conformation with a plurality of turns 2 encompassing the horizontal length 6 which latter preferably extends axially'of said spiral winding. The loop bend 7 desirably is formed within the cylindrical contour of the helical coil. When at the completion of the helix unit the innermost end of the spiral winding is Once more opposite the inlet end 3 of the horizontal length 6 the tubing is again axially turned so as to be parallel and adjacent to its inlet end 3, and an end similar to that of the inlet is formed and a similar fitting 8 is provided thereat. The fittings which may be of cast brass or other suitable metal, are brazed, welded or otherwise joined to the tubing ends, such fittings having been suitably threaded for connection to conventional water pipes 5. Brazing is preferable in this instance since it will create a junction stronger than the copper itself and will prevent loosening, corrosion or separation and is particularly impervious to high temperatures.

The above described embodiment is fully satisfactory for most uses and in fact is preferable. It is also possible to provide other embodiments, one of which is shown in Fig. 5. In this form shown the inlet horizontal length need not be disposed axially within the helix but may be disposed parallel to the axis immediately outside the helical coil. The method of construction in this instance is that the coil is first forrmed and at the end of the desired number of turns the tube 2a is turned through a suitable loop bend and brought back as a horizontal length axially positioned outside and adjacent to the coil, and thereupon the respective tubing extremities are ended and fitted identically as in the previously described embodiment.

The two helical coils thus provided may be of the same length or one may be shorter than the other depending upon the size and form of the passageway within the dome section of the boiler burner unit into which the device is to be installed. In the preferred embodiment shown in Fig. 1, one coil is shorter than its twin so as to permit and facilitate ready insertion, manipulation, fitting and assembly within the said dome section.

The helical coils may have an outer diameter of 3 to 4 inches and have approximately 20 turns. In the embodiment shown in. Fig. 1, the shorter coil may have approximately 15 turns. The copper tubing may be inches outer diameter and /2 inch inner diameter. .The

convenient type and height usually accompanying respec tive and corresponding tube diameters. The loop bend 7 may be an angle, elbow or other suitable bend but preferably formed within the cylindrical contour and length of the helical coil. The length of the coils, fitting and all, may be approximately 20 inches. Or as is shown in Fig. l, the length of the shorter coil may be approximately 15 inches. The dimensions given are neither absolute nor to be taken as critical but they conform to and approximate a commercially practical structure. Other lengths, numbers and dimensions, of course, may 'be utilized in any given case as desired and prove equally effective. 7

The device is fitted with a suitable gasket 9 to produce tight joint, a cover plate 11 having four openings to receive the fittings 4 and 8, respectively, of the four ends of coils 1, such cover plate 11 being adapted to fit the particular opening of the dome section 12 of the boiler burner unit, and lock nuts 14 suitably fitted over gaskets 15 to seat the unit firmly in place.

In installation the blank cover plate in the opening to the dome section of the boiler unit selected is first removed. The device herein described is dissassembled. The shorter or first coil 1 is inserted horizontally within the dome section 12 of the boiler unit and is preferably placed into the left side of the dome section. This shorter coil can be pushed in far enough to clear the opening to the dome section. The longer twin coil 1 may then be inserted similarly horizontally into the right side of the domesection. It is desirable to insert each of said coils so that the axially disposed horizontal length 6 of each of them is on top. Nevertheless, it is emphasized that the invention herein disclosed embraces within its scope the entire unit, regardless of the mode of installation or its use. Because of the flexibility of the coils they may be bent carefully to facilitate their fitting therewithin without fear of damage and when finally fitted therein will preferably be disposed in a V-shape with the front end fittings 4 and 8, respectively, positioned so as to form the corners of a square, as is more particularly shown in Fig. 2. Thereupon four nipples or other convenient holders may be run loosely into the said fittings for use as grips to permit the setting of the fittings firmly against the cover plate 11 provided. When the coil fittings bearing their gaskets 15 are centered in the holes provided therefor in the cover plate 11, the lock nuts 14 may be firmly seated in place whereupon the cover plate 11 may be bolted to the boiler unit, and the device is then ready for use.

Depending upon the size, the form and the passages in dome sections of divers standard type boiler burner units, it is also possible to provide a structure having twin helical coils disposed in any convenient geometrical fashion other than the V-shape shown in Figs. 1 and 5. Thus the twin coils may be parallel, circular or set at any convenient angle. Similarly, the twin coils may be in ternally attached to each other within the dome section by bolts, fasteners, slot and tongue members or by any other suitable or appropriate supports.

In the use of the device, after the same has been installed within the boiler unit, an external pipe series connection 16 from one section of one coil to the diagonally opposing section of the other coil is made, and the other two openings are used for connection to the cold water inlet and hot water flow pipes 5, respectively, of the premises in use, as is particularly well shown in Fig. 6. Thus, when the boiler burner unit is in operation and hot water is called for, cold water will enter one of the inlets 5, proceed through the horizontal length and its own helix, through the horizontal length of the twin and the twin helix and emerge as hot water through the outlet 5, for instant domestic use. This procedure may continue at will and for as long a period of time as the user may desire. h 7

Thus, by use of the twin helixes a high additional area of square feet of heating surface is provided, aided y the finned tubing thereon, which necessarily results in a correspondingly high equivalent rating of gallons of hot water per minute at divers temperatures of boiler water in the unit. For example, it has been found that 12 square feet of heating surface has an equivalent rating of 4 gallons per minute at F. boiler water; that 15 square feet of heating surface has an equivalent rating of 5 gallons per minute at 180 F. boiler water; and that 18 square feet of heating surface has an equivalent rating of 6 gallons per minute at 180 F. boiler water, and so on. Additionally, the helical coils serve the purpose of reducing fouling and water pressure loss to a minimum.

The structure is peculiarly adapted for disassembly into a compact package for shipment and storage and is characterized by the fact that it is readily assembled and installed at the site of the use with a minimum of effort. Equally, it may be easily removed for inspection or drainmg.

There is thus provided by this invention a highly utilitarian structure which is extremely durable, elficient and effective, simply and sturdily constructed, exceptionally easy to install in a standard type boiler burner unit, inexpensive in cost and installation, yet once installed will furnish a constant and abundant supply of clean, hot water for all domestic uses during the entire period the boiler burner unit is in operation, at the lowest possible cost.

While there are above disclosed but a limited number of embodiments of the device of the present invention it is possible to provide still other embodiments without departing from the inventive concept herein disclosed, and it is therefore desired that only such limitations be imposed on the appended claims as are stated therein or required by the prior art.

The invention claimed is:

1. In a domestic hot water heating system utilizing heat in a boiler having piping therein; a tankless heater coil unit comprising coiled lengths of tubing for heat transfer fitted into said boiler by bending and angling the said coils, a cover plate for a boiler opening, the ends of the coils passing through said cover plate, bolted over an opening in said boiler; the heating coil units consisting of a plurality of flexible helically wound tubes having a straight portion at one end :of the helix, parallel to the axis of said helix, a portion of said tube being brought back along the helix into a position parallel to the initial end of the helix, the two helices being of different lengths, the said plate having four openings therein adapted to pressure-tight closure over the said boiler opening, the said helices being bent in a curved contour to pass between tubular structures within said boiler and the entrance and exit ends being fitted at an angle to each other.

2. In a domestic hot water heating system utilizing heat in a boiler having piping therein; a tank'less heater coil unit comprising coiled lengths of finned tubing for heat transfer fitted into said boiler by bending and angling the said coils, a cover plate for a boiler opening, the ends of the coils passing through said cover plate, bolted over an opening in said boiler; :the heating coil units consisting of a plurality of flexible helically wound tubes having a straight portion at one end of the helix, parallel to the axis of said helix, a portion of said finned tube being brought back along the helix into a position parallel .to the initial end of the helix, the two helices being of different lengths, the said plate having'four openings therein adapted to pressure-tight closure over the said boiler opening, the said tubes in the said helices being provided with projecting fins to increase the heat transfer capacity, the said helices being bent in a curved contour to pass between tubular structures within said boiler and the entrance and exit ends being fitted at an angle to each other; such unit being characterized by the ability .to assemble, mount, demount anddissassemb'le the unit.

3. The structure of claim 1 wherein the return length of the heater tube is-positioned axially within. the helix portion of the tube. r

References Cited in the file of this patent UNITED STATES PATENTS Dahl July 29, 1913 Schneible Feb. 1, 1921 Smith Sept. 16, 1930 Muhleisen Aug. 18, 1931 Wineman Dec. 26, 1944 Donohue Nov. 11, 1952 Borg Dec. 16, 1952 

